ROBERT SIEGEL, HOST:
We are surrounded by living creatures too small to see, like bacteria, and we're learning gradually how much we depend on them. Microbes inside us help fight off disease. In the soil, they deliver nutrients to plants, and some big companies are now betting they can turn soil microbes into tools that farmers can use to grow more food. NPR's Dan Charles reports.
DAN CHARLES, BYLINE: One way to use microbes in farming is to deploy them as weapons to fight off insects or weeds. Pam Marrone, who's founder of Marrone Bio Innovations in Davis, Calif., has spent most of her life looking for such microbial pesticides. She shows me a few candidates, colonies of microorganisms growing in little round petri dishes. Some are fuzzy, some slimy. Marrone thinks they're beautiful.
PAM MARRONE: They're all different colors. You've got orange, blue, purple, black, boring tan and magenta.
CHARLES: Interesting to look at, but the real test will be if they can kill other living creatures in this lab, like crop-eating insects.
MARRONE: We have cabbage loopers, beat army worms, corn rootworms, green peach aphids, spider mites.
CHARLES: Marrone is also looking for microbes that kill weeds. She thinks she may have found one.
MARRONE: Here you see some of the bacteria growing in this larger pilot vessel.
CHARLES: Any idea what we're growing here?
MARRONE: This is my favorite herbicidal microbe.
CHARLES: This microbe came from soil collected from the garden of a Buddhist temple in Japan. It doesn't harm insects, but it kills a lot of vegetation. Marrone thinks it might eventually be a weed killer that organic farmers can use. She says there's huge demand for such a thing.
MARRONE: I can go into a chemical distributor in the Central Valley of California and say, what is your unmet - biggest unmet need, and honest to God, this chemical distributor dealer will tell me organic weed control. It's remarkable.
CHARLES: Marrone is hoping to submit this microbe to the Environmental Protection Agency for approval later this year. So-called biopesticides have always been popular in small corners of agriculture like organic farming. Now though, big chemical companies are jumping in. It's partly because organic farming is growing, but even conventional farmers are under pressure to use fewer toxic chemicals. And alongside this search for natural pesticides, there's an even bigger boom in a whole new way to use microbes on the farm. It's what you might call probiotics for crops. These are microbes that, for whatever reason, seem to give crops a boost.
MATTHEW ASHBY: We don't know how they work necessarily.
CHARLES: This is Matthew Ashby, the founder and chief scientist of a tiny startup company called Taxon Biosciences in Tiburon, Calif. On the wall at Taxon, there's a computer printout that reaches from ceiling to floor. It's a list of all the microbes that Taxon found in about 100 different soil samples. Each microbe is identified by its DNA sequence, and there are a lot of microbes.
ASHBY: I just asked our sequencing manager to print out 8 feet of this so it would fit on the wall. If we printed out the entire data set, it'd be over a mile long.
CHARLES: Ashby says take a close look at this overwhelming list and you find hints to what the microbes do. For instance, some microbes show up consistently in soil samples from fields that produce bumper harvests of corn.
ASHBY: You know, when you always find a microbe there when a plant is doing well, there might be something to that.
CHARLES: Maybe those microbes are making corn more productive. In small test plots, adding those microbes to the soil made the corn plants grow faster. A year and a half ago, DuPont, the giant multinational that sells pesticides and seeds, among many other things, came to visit this little start up. Frank DeGennaro, director of DuPont Biologicals, was on that trip. He says they were really impressed.
FRANK DEGENNARO: The car ride home was constant, holy cow, you know? They were going on and on and on through the windy roads of Tiburon. And I said, I think there's something here. You know, we should have another discussion.
CHARLES: In April, DuPont announced it was buying Taxon. This summer, at thousands of spots across the Midwest, it's carrying out field trials to see if Taxon's microbes really do boost corn yields. And other big companies that sell pesticides and seeds like Monsanto, Bayer, Syngenta, have made similar deals - even bigger deals, in fact. All of them are betting that the next great tool that farmers use to grow more food may be found in the soil under our feet. Dan Charles, NPR News.
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